Identify the effects of excess water during early grape growth, ie: preverasion.
if water is too easily available into late spring and early summer, vegetative growth (the growth of shoots and leaves) is promoted and prolonged into the period of grape ripening. This acts as a competitive source for the vine’s sugars, which can delay and compromise ripening. It is therefore thought that mild water stress before véraison is beneficial as it inhibits further vegetative growth.
Identify three factors that affect nutrient availability for the vine.
- soil pH
- soil texture
- topography
Identify three decisions that a vineyard manager could make to counteract the effect of rising temperatures in their vineyard due to climate change.
- site selection
- choice of planting material
- efficacy of different vineyard management techniques
Identify the aims of sustainable viticulture.
- promote the natural ecosystems in the vineyard
- maintain biodiversity
- manage waste
- minimise applications of chemicals and energy use
- reduce the impact of viticulture on the wider environment
Identify 5 factors that would determine the suitability of land for the planting of a new vineyard.
- natural resources (location, layout, topography)
- price of the land
- suitability of mechanisation
- irrigation
- ease of access (vineyards and winery)
Identify 5 techniques for improving the soil texture or structure before planting a new vineyard.
- remove very large rocks at or near surface
- subsoiling (process of breaking down a plough pan - an
impervious layer of soil) - remove and burn old roots
- apply farmyard manure, compost and fertilisers
- adjust soil pH
Identify 4 factors to consider when choosing species of rootstock planting material.
- pests
- water
- soil pH
- vigour
Identify an appropriate choice of rootstock for a vineyard that is prone to root-knot nematodes.
Ramsey and Dog Ridge (both Vitis champini)
Identify the possible disadvantages of cultivation.
- Repeated cultivation can damage the soil’s structure and ecology due to the breakdown of organic matter and disruption of earthworms in their habitat.
- It is costly as it requires both skilled labour and machinery.
- Disturbing the soil buries seeds, thus encouraging the weeds to grow back.
- It can increase vine vigour too much as there is no competition for water or nutrients (not necessarily a disadvantage in low vigour sites (poor soils and/or lack of water)).
Identify the natural and artificial methods for improving vineyard drainage.
- leaving natural vegetation to grow or planting specific crops to provide competition for water, leaving less available for the vine
- Improving soil structure and removing any plough pans to better regulate water drainage
- Drainage pipe installation before planting the vineyard
Identify four of the goals pertaining to canopy management.
- maximise the effectiveness of light interception
- promote air circulation through the canopy to reduce incidence of disease
- arrange the vine canopy to ease mechanisation and/or manual labour
- reduce the shade within the canopy
Identify 7 types of summer pruning.
disbudding
–
shoot removal
–
shoot positioning
–
pinching
–
shoot trimming
–
leaf removal
–
crop thinning/green harvesting
Identify three ways that a vineyard can be managed to reduce the threat of frost.
- site selection (choose hillsides, avoid frost pockets)
- choose late-budding varieties (e.g. Riesling) and /or delay pruning
- Vines trained high off the ground offer more protection, as the coldest air is near the ground.
Identify the symptoms of phylloxera.
- Vines die of drought in patches that increase in size year by year
- Vine roots are covered with the insects surrounded by yellow eggs
- Swellings on older roots
- Pale green leaf galls on the under-surface of the leaves
- Slow, stunted shoot growth and leaf yellowing appears in around three years, the plant dies after around five years.
Identify three management techniques for grape moths.
Biological controls include the use of:
– the bacterium Bacillus thuringiensis (which produces substances that are toxic to the moths)
– use of pheromone capsules to disrupt mating (‘sexual confusion’)
– natural predators (parasitic wasps, green lacewings, some spider species).
Identify 4 techniques that vineyards can use to control grey rot.
- Selecting grape varieties that have small grapes with thick skins and therefore high levels of resistance (e.g. Petit Verdot) and protecting the grapes against other pests (which could split the skin of the grape) are the most important options.
- Keeping an open canopy and removing the leaves around bunches can also reduce the spread of grey rot.
- Traditional sulfur and copper sprays are ineffective, but other fungicides can be used. They should be applied at key points in the season – when flowering is nearly complete, at the end of grape formation, at bunch closure (when the grapes in a bunch get large
enough so that they touch each other) and véraison. However, fungicides quickly become ineffective if the fungus develops resistance. - Attention has therefore turned to using antagonistic bacteria; for example, Bacillus subtilis and other forms of biological control.
Identity 4 management techniques for mitigating Esca.
- sourcing disease-free stock,
- trying new, less detrimental, pruning techniques,
- not pruning in the rain,
- removing prunings promptly from the vineyard and disinfecting pruning wounds.
Identify the symptoms of grapevine yellows.
delayed budburst, a drooping posture because the new shoots fail to become woody, and the canopy turning yellow (in white varieties) and red (in black varieties). In some strains, the vine dies as the disease progresses, in others it can recover after an attack.
Identify three ways that the quality of fruit can be improved when using a mechanical harvesting approach.
- selecting out undesirable fruit by hand before harvesting by machine
- using a bow-rod shaking machine (rather than the older machines, which beat vines to remove the fruit); this is gentler and can be set to be more selective
- investing in the very latest machines that have options for optical sorting devices on them and which can crush white grapes and add SO2 in the machine itself to limit oxidation
- rigorous sorting on arrival in the winery, including removal of MOG (matter other than grapes) and unripe and rotten grapes.
Identify 4 situations that would require hand harvesting.
- premium sparkling wines made where whole bunches are required for whole bunch pressing (Champagne and most bottlefermented sparkling wine around the world).
- grapes for Beaujolais and other wines that will be made by carbonic or semi-carbonic maceration require whole bunches for the process
- if making a style of wine that requires selective harvesting of certain
grapes, harvesting must be done by hand. For example, pickers may be instructed to harvest only botrytis-affected bunches (e.g. for Trockenbeerenauslese Riesling in the Mosel) - where they are grown on steep slopes (e.g. in the Douro
Valley) or uneven land. Bush vines are harvested by hand
Identify 4 positive attributes of wines with a low pH.
A low pH
1. increases the microbiological stability of wine,
2. increases the effectiveness of SO2,
3. gives red wines a bright red colour
4. enhances a wine’s ability to age well.
Identify the 4 sources of aromatics in a wine.
- Aromas from the Grapes
- Aromas created by Fermentation due to the Presence of Aroma Precursors in Grape Must
- Aromas originating from Fermentation and its By-products
- Aromas from Other Sources (e.g. vanillin, eucalyptol)
Identify the 4 levels of still wine residual sugar classification in the EU.
- Dry/sec/trocken etc. – up to 4 g/L RS, or not exceeding 9 g/L provided that total acidity expressed as grams of tartaric acid per litre is not more than 2 g below RS content. For
example, a wine with 9 g/L RS can be labelled ‘Sec’ if it has 7 g/L total acidity. - Medium dry/demi-sec/halbtrocken etc. – more than 4 g/L and not more than 12 g/L RS, or up to 18 g/L provided that the total acidity expressed as grams of tartaric acid per litre is not more than 10 g below the RS content.
- Medium or medium sweet/moelleux/lieblich etc. – more than 12 g/L and not exceeding 45 g/L RS.
- Sweet/doux/süss etc. – at least 45 g/L RS.
Identify at least 4 methods used to increase oxygen exposure to must and wines.
Oxygen exposure can be increased by:
*
use of cap management techniques in red wine fermentation that spray or splash the must or wine
*
use of small wooden barrels that can only contain a small volume of wine relative to the amount of oxygen that enters through the bung holes and staves
*
increasing the number of rackings or amount of lees stirring during ageing; any procedures that require the bung of a barrel or lid of a vessel to be removed and the wine to be moved will increase oxygen exposure
*
allowing ullage in wine containers without the use of inert gases in the headspace
*
use of techniques that involve pumping oxygen through the must (e.g. hyperoxidation) or wine (e.g. micro-oxygenation)
